A relevant drive for a cold pilger rolling mill is known, for example, from DE 43 36 422 C2. To carry out the cold pilger process, a rolling mill equipped with a cold pilger roll pair is required which can be driven in an oscillating manner. For this purpose a crank drive is used which is driven by a motor. The crank drive is provided with a counterweight to compensate for the inertial forces of the mill stand. However, this weight does not satisfy all of the requirements for a sufficient compensation of the inertial forces and moments of inertia.
The productivity of a cold pilger rolling mill is directly dependent upon the stroke count of the mill stand per unit time which, from the point of view of economy, should have the maximum number of working strokes per minute. This means however that both the drive system and its bearings as well as the foundation and its environment must be subject to large inertial forces.
In DE 43 36 422 C2 it is thus provided that the crank drive, in turn, drives a further shaft via gearing and upon which a counterweight is arranged eccentrically with respect to the center of gravity. This counterweight runs upon rotation in the opposite sense to the crank drive and is in such a position as to generate inertial forces or moments of inertia which are compensatory so that over all an inertial force compensation will be obtained in the entire drive system.
It is a drawback of the known configuration that as a whole it results in a quite expensive construction of the overall drive system because a multiplicity of machine elements, meshing with one another by gearing, is required. As a result there is an increase also in the cost of the drive system and thus of the cold pilger rolling mill, applicable not only to the investment cost for the apparatus itself, but also the cost for the foundation for the apparatus, for replacement and wear parts, and for maintenance and repair.
From German patent DE PS 962 062, a drive system for a cold pilger rolling mill is known in which the crankshaft for driving the mill frame is equipped with centrifugal weights and a vertically oscillating compensating weight for compensating for first order inertial forces as well as the moments of inertia in is the drive.
It is a disadvantage with this solution that the foundation of the rolling mill is very expensive and of high cost construction since the vertical penetration of the compensating weights into the foundation must be provided for. As a consequence a larger and deeper cellar is required which correspondingly increases the cost of the rolling mill.
DE 36/3036 C1 discloses a drive for a rolling mill frame in which a planetary crank drive is used for driving and compensating for the inertial forces and moments of inertia.
When an optimal inertial compensation can be achieved with this solution, the drive is satisfactory only for small cold pilger rolling mills because with larger apparatuses, the size of the drive system increases overproportionally and gives rise to higher costs.
All known drive systems for cold pilger rolling mills thus have serious disadvantages whether they involve insufficient reduction of the inertial forces or moments of inertia, high capital or foundation costs and/or an expensive mounting during the fabrication or in repair and maintenance.